Adhesive disc precursor secretions will be collected from the distal depression of the foot of the sea mussel Mytilus edulis after chemically stimulating the secretory process. Secretions will be stored in NaCN or acetylimidazole to prevent hardening. Protein components of the secretions will be isolated and purified using column chromatography and polyacrylamide disc gel electrophoresis. Particular emphasis will be placed on characterizing the enzymic component of the adhesive. Experiments to obtain adhesive disc precursors from isolated secretory vesicles will also be initiated. Research will be continued to study the mechanism of the hardening process by following the formation of tyrosine cross-links in chemically and enzymically treated precursor secretions and in similarly treated precursor secretion fractions and fraction combinations. Finally, it is expected that preliminary experiments will be conducted to demonstrate in vitro formation of hardened adhesive material from precursor secretions. Results from these experiments could ultimately lead to the application of the secretion as a hard tissue adhesive. BIBLIOGRAPHIC REFERENCES: DeVore, D.P., and Gruebel, R.J., "Identification of Dityrosine in Adhesive Discs formed by Mytilus edulis", (Abstract Approved for Presentation at FASEB Meetings April 1, 1977, to April 7, 1977).